Piston ring



April 23, 1929. I; MCK 1,710,485

PISTON RING Filed Feb. 9, 1927 the pistons.

Patented Apr. 23,

ATENT OFFICE.

' mo J. MCKONE, or MI NEAPOLIS; mmunsom.

rrs'rou alive.

Application; filed February 9, 1927. Serial No. 188,954.

This invention relates to a piston ring and while the invention is particularly designed for use in the piston of an automobile engine, it is capable of application with other types of pistons. In modern high speed automobile engines, difficulty is experienced in "maintaining a proper film of oil between the piston rings and the cylinder wall. Unless the film of oil is maintained between these parts, undue friction occurs .on the cylinder wall and the ring and wall become heated so that the wall is abraded and the cylinder thus damaged and given an out-of-round shape. If wide rings are used, it has been difficult to properly supply-oil to the surface thereof and it has become more or less of a common practice tofuse narrow oil rings in lhe oil film, however, breaks down on the narrow rings and serious damage to the cylinder wall and rings result.

It is an object of this invention, therefore,

to provide a ring which can be made of considerable width and to wh'ich'the'oil can effectively be distributed. a

'It is a further object'of the invention to provide a ring which can be made of considerable width, which ring has recesses in its wearing surface, with means fon supplying oil to said surface through said recesses. I.

It is still another object of the invention to provide a ring'which has a stepped formation on its inner side fitting a like formation. in

the piston ring groove and which has recesses: on its wearing surface in communication withsaid steps on its inner side.

It is still provide a pi hton and ring structure in which the piston has ring grooves with stepped formation in which fit stepped rings so that a recess or passage is formed between the rings and piston, saidring having grooves in its outer surface connected by passages with its stepped surface. a

These'and other ob'ects and advantages of the invention will be ully set forth in the following description made in connection with ,the. accompanying drawings, in which-like reference characters refer to similar parts throughout the several views and in which Fig. 1 is a view partly in radial section and partly in side elevation showing-a portion of the piston and cylinder wall with the rings therein; I

' Fi 2 is a view similar to Fig. 1 showing theI rings in the piston in another position;

an a

-thus bein sectlon.

to leave an opening or recess 7 between their nother ob ect of the invention to Fig. 3 is used.

a perspective view of the ring Referring to the drawings, a piston 5 is shown such asnow'commonly used in an in-.

ternal combustion or automobile engine. 2

Said piston has ring grooves 5 formed there-; in and in the embodiment of the invention illustrated these grooves are of stepped formation or formed with successive angular portions '5"; While the angle'of these portions might be varied,'in the embodiment of the invention illustrated they-are shown as right angular. The .grooves 5 have rings 6 discesses 5 of the I of mg t angular shape in cross he rings 6 are-of a size, however,

inner sides and the surface of'the ring grooves; The ring 6'is also provided'on its outer. surface with a plurality of slots 6" and while these slots may be of various shapes, in-

in shape in cross section. The slot 6 as clearly shown in the drawings, extend in a direc' tion inclined to the top and bottom surface 'of the ring and it will be seen that said grooves overlap at their ends. Comparatively small holes 6 extend from the bottom of the grooves 6 at an intermediate point therein to the inner side of said ring. I A 2 I When the engine is operating and the pistonis moving upwardly in the cylinder, the

1, ring will occu y the position shown in Fig; 1.

It will be un erstood that as usual the ring is under some tension to expand and engage thecylinder wall although this tension must be of such small degree as to permit the movement of the ring transversely of the groove in Y the movements of said iston. With the described structure oil will be forced into the recess between the piston 5 and the ring 6 into the grooves 6" and will e distributed on the cylinder wall and the ring wearing surface. This action is as follows above the piston at this time forces the oil land this oil'will pass throu h the passage 6 along the side of the piston above the ring and into the recess'7. This oil being under piston moves upward on'the exhaust stroke;

' the piston moves downwardly in the intake,

the upper surface of the steps on the ring pressure of approximately 100 pounds per square inch, will be forced through the piessages 6 into the grooves 6 and will be distributed over the wearing surface of the'ring. The same action will take place when the At this time there is approximately a pressure of 40 pounds per square inch in the cylinder.

The *ring will also usually assume the position shown in Fig. 1 just after the expansion in the cylinder as the high-pressure in the cylinder which is at this time usually over 400 pounds per square inch, will force the oil will also at this time be forced into the recess 7 and through the passages 6 'When stroke and possibly during the latter part of the power stroke, the ring will take the position shown in Fig. 2. As shown in Fig. 2,

and piston are then in contact.- The inner end of the passages 6, will thus be s'ealedfrom the upperjend of the piston so thatloil cannot be sucked from the grooves 6* through the passages 6, If it were not for this seal, this'action would take place. "The ring thus grooved; The wearin surface of the ring is thus effectively supp ied with oil and. the film of oil between the ring and the cylinder wall is continuously maintained.

From theabove' description it is seen that .applicant has provided a very simple and eflicient structure of piston ring and one tice and has which e'fi ectively maintains the proper lubrication. tion and easily made-andinstalled. 7 The device has been given long tests in actual praceiiicient. y I It will, of course, be understood that various changes may be made in thet'orm, details,

The ring is of simple construe proven to be very successitul'and arrangement and proportionsjof' the parts,

without departing -from the scope of applicants invention, which, generally stated,

consistsin a device capable of carrying-out the objects above set forth, in the novel parts I and combinations of parts disclosed and'de fined in the appended claims.

" 1. Apistonring having a plurality of steps on its inner fside dapted to fit correiiiston so as to leavea passage? between said ring and piston, said ring having a luralit of spaced circumferring toits lowest position in the piston. The

spending stepson the ential grooves ormed n its'outer surface and passages leading from said her sideof sa d-rmg.

*2. A piston r ng having its inner side .formed with a'plurality of stepped recesses of rightangular shape in radial cross section, said ring having a plurality of spaced cir cumferential grooves on its outer surface, and a passage leading 'fromthe bottom of each groovesto the ingroove to the inner side of said ring, said groove being inclined "to the top and bottom surfacesiof said ring and overlapping at their ends.

3. Ai piston and ring structure comprising piston having an imperforate wall with a stepped ring groove there1n,sa d groove being narrowest at its upper portion, a ring disposed in said groove andsteppsd at'its nner portion to fit said groove, said rlng thusbeing widest at its lower portion, said ring being thinner than the depth of spid groove so as to leave a passage between he inner side of said ring-and'the inner wall of said'g'roove,

said piston thus acting'to seal said passage by "In testimony whereof Iatfixmy signature.

aos, Marcus. 

